Without the extraordinary efforts of Allied code breakers, the outcome of World War II might have been very different. Moving across the world from Bletchley Park to Pearl Harbor, and from Mombasa to Melbourne, this book reveals how Japan's military codes were broken in a whirlwind race between American and British code breakers and explains step by step how they accomplished this daunting task. Drawing on recently declassified files, privileged access to secret official histories, and interviews with many of the men involved, Michael Smith offers this "real-life thriller that unfolds like a classic spy story" (Booklist).